Source : Webster's Revised Unabridged Dictionary (1913)

Windpipe \Wind"pipe`\, n. (Anat.)
   The passage for the breath from the larynx to the lungs; the
   trachea; the weasand. See Illust. under {Lung}.

Source : WordNet®

windpipe
     n : membranous tube with cartilaginous rings that conveys
         inhaled air from the larynx to the bronchi [syn: {trachea}]